Signal mechanism



Aug. 10, 1954 J. R. BARR SIGNAL MECHANISM Filed Aug. 24, 195:5

Patented Aug. 10, 1954 SIGNAL MECHANISM James R. Barr, Pittsfield, Mass., assignor to General Electric Company, a corporation of New York Application August 24, 1953, Serial No. 376,218

5 Claims. l

This invention relates to a signal mechanism, and more particularly, to a signal mechanism employing an electric light.

Signal mechanisms employing an electric light adapted to be illuminated to signal the occurrence of some event to apprise one of said occurrence are well known in the art. Some forms of said signal -mechanisms have means for resetting said signal mechanism after they have given a first signal so that they will be ready to give a subsequent signal. However, as far as I am aware, none of the signal mechanisms having resetting means make provision for automatically and conveniently checking the electric light used and the electrical circuit of the signal mechanism to make sure that said circuit has not become defective or inoperative. Conventionally, the electric light bulb is checked by removing it from the signal mechanism and trying it out in another electrical circuit to make sure that the electric light bulb has not blown.

It is an object of this invention to provide in a signal mechanism having an electric light signal and a resetting mechanism, means for automatically and conveniently checking the electric light bulb and the circuit therefor to make sure that they are in an operative condition.

In a signal mechanism having an electric light and a resetting mechanism, my invention comprises means for automatically and conveniently checking the operativeness of the electric light and the electrical circuit therefor.

The invention will be better understood by considering the following description taken in connection with the accompanying drawing and its scope will be pointed out in the appended claims.

In the drawing Fig. l is a side view, partly in section, of an embodiment of my invention. Fig. 2 is a top view of the toggle spring switch arm of the device shown in Fig. 1.

Referring to the drawing, shown therein is a signal mechanism enclosed within a housing I0. Housing I is mounted on and carried by a tank side wall of a transformer apparatus comprising a magnetic core, not shown, and electrical windings I2. As is well known in the transformer art the magnetic core and electrical windings I2 of the transformer apparatus are enclosed within a tank of which side wall I I is a part. If so desired, the magnetic core and electrical windings can be submerged within a dielectric liquid contained within the transformer tank.

The transformer tank is grounded, as illustrated by ground lead I3. Accordingly, the housing I0 is also connected to ground inasmuch as housing I0 abuts and is in electrical contact with side wall of the grounded transformer tank.

Positioned within the electrical windings l2 is a bulb i@ containing a thermally responsive liquid therein. Bulb I4 is connected by a capillary tube |5 to a bellows actuator IS mounted within housing ill. As is well known. in the art, when the electrical windings I2 heat up beyond a predetermined temperature the liquid within bulb I4 will vaporize. The resulting vapor will cause an increase in pressure Within bellows actuator I6 and cause it to expand.

Mounted directly below the bellows actuator IG is an insulating material support |'I carrying a toggle spring switch arm. The toggle spring arm comprises a generally ilat elongated rectangular-like strip of thin resilient metal. As seen more clearly in Fig. 2, a wide I-like hole I8 is punched in the forward half of said strip of resilient metal between the central and forward portions thereof leaving two opposed tabs I9. Between the tabs i9 is inserted a coil spring 20, said spring 2U being carried and centered by said tabs I9 inasmuch as tabs I9 enter opposite end portions of said coil spring 20. Extending from the top and bottom edges of I-like hole I8 are two thin parallel slots 2|. Slots 2| extend towards but short of the left hand end edge when viewing Fig. 2, of said strip of resilient metal. Between slots 2| is formed a depressed portion 22. The underside of said depressed portion 22 is placed against an upper surface of insulating material support |'I and the toggle spring switch arm is fastened to said support, as by bolt means 23 passing through depressed portion 22 and insulating material support Il.

As will be apparent to those skilled in the art, when the toggle spring switch arm is in its unilexed condition the leaf spring-like portions 24 defined by slots 2| and I-like hole i8 will lie in .the horizontal plane of the strip of resilient metal, and tabs I9 will be aligned opposite to each other in said horizontal plane. Said horizontal plane is indicated in Fig. l by dead-center line 25 containing the non-depressed portion 26 positioned between slots 2|. When leaf springlike portions 24 are flexed upwardly above dead center or plane 25 about their fixed ends 2, the coil spring 20 will also be flexed upwardly. When the coil spring 20 is ilexed upwardly a suflicient amount, as shown by the Fig. l position of my toggle spring switch arm, the coil spring 20 will restrain the leaf spring-like portions 24 from returning to dead center. Similarly, when the 'material gaskets.

determined temperature.

'below dead center. portions 24 flexed below dead center'the upper toggle spring switch arm is iiexed below dead center, as indicated by the Fig. l broken-line position of my toggle spring switch arm the coil spring 20 will restrain my toggle spring switch arm from returning back to dead center.

Carried by leaf spring-like portions 24 is a U-shaped member bent into an L-shape, when viewedfrom the side, as shown in Fig. 1. The forward leg portions 28 of the U-shaped member are superposed with respect to and fastened to leaf spring-like potrions 24, as by rivets. The base portion 29 of the U-shaped member is positioned opposite to bellows actuator I6 and sufficiently above the horizontal plane A-Ziiof ythe toggle spring switch arm so that it will notlabutnon-depressed portion '26 to prohibit the toggle spring switch arm from being flexed below dead center.

Connected to the forward end of the toggle spring switch arm is a resilient V or t'J-shap'ed contact member 30. Mounted within housing I is'another insulating material support 3| carrying another contact member having a V or U- shaped contact portion 32. The V'or U-shaped contact portion 32 is ygenerally disposed within V or U-shaped Contact member 30 so that the legs of member 30 embraced the legs of contact portion 32. 'Mounted atthe forward end of/housing I0 is an electric light bulb 33 in electrical -contact with electrically grounded housing I0 and contact portion 32. The electrical windings I2of the transfoimei'constitute a source of electrical power for operating the electric light bulb 33, as by having a tap lead 34 of suitable voltage extending from said windings I2 to a bolt means 35, or by having separate electrical windings provided vfor this purpose. Bolt means 35 is insulated from the vgrounded housing i0 and vgrounded tank wall `I I, as by suitable insulating Electrical contact is made between bolt means 35 and bolt means`23, 4as by a connecting strip 36. `Positioned below the contact member 30 is an insulating material plunger V3l, and as will appear more'clearly hereinafter, depression 'of plunger 3l will reset the signal mechanism andalso conveniently and automatically-check the operativeness of the electric light V`occurrence of a temperature rise in the windings I2 of thetransformer apparatus beyond a pre- Should the electrical windings I2 heat up beyond said predetermined temperature the liquid within bulb I4 will va- -porize and expand bellowsactuator I6. The'bel- 'lowsactuator I6 will thereupon strike Van insulating material button I38 on the base portionV 29 and cause the leaf spring-like portions 24to be flexed With the leaf spring-like leg 39 of contact member 30 will be placed in electrical contact with the upper leg 43 of contact portion 32. The'electrical circuit for the electric light bulb 33 is now complete and electric light bulb 33 will now light up to signal'the occurrence of a temperature rise in windings I2 beyond said predetermined temperature. The electrical circuit for bulb 33 comprises taplead 34, bolt means 35, connecting strip'36, bolt lmeans 23, the toggle spring switch arm, contact member `30, contact portion 32, electric light bulb 33, housing Il), and grounded tank side wall-I I. This `closed circuit will be maintained even if said temperature rise condition in the transformer apparatus ceases since when the toggle vspring I -contact with each other.

be as shownin Fig. lftiythef-broken-line outline of my toggle spring switch arm.

After the cause for said temperatm'e rise has been determined and corrected the signal mechanism can be reset to be prepared to signal a subsequent temperature rise by depressing plunger '31. 1Partial depression of plunger 3l will iiex the vtoggle-spring switch arm above dead center or plane 25 and cil'ls'pring 20 will restrain the toggle springswitch arm from iiexing back to dead cen- `t'r. JThus, Y'as shown by the full-line position in Fig. l of the toggle spring switch arm, the upper legs 39 and 40 are no longer in electrical Also, the lower leg or auxiliary contact portionofcontact member 30 is spaced from the lower leg 42 `of contact `portion 32. The electrical circuit for the velectric iight bulb v a3 is now broken and the electricught The operativeness of the electrical ycircuit for electricllight bulb 33 and the electric light bulb 33 can be convenientlyrchecked' at any time-by merely depressing the plunger -31 until it-causes the lower'leg or auxiliary contact portion 4I to come intoelectrical contact with lower leg 42. Whenflegs 4I -and 42 contact each other the electrical circuit through the electric light bulb is complete and it will light up. If it does not light up, then one is apprised of the fact that either the electric light bulb 33 or the electric circuit therefore" is inoperative.

While there has been shown and describeda `particular embodiment of the invention, it will be obvious to those skilled in the art that changes and modifications may be made without departing from the invention, and that it is intended in the appended claims tol cover all such changes and modifications as fall vwithin the true spirit and scope of the invention.

What I claim as new and desire lto secure vby Letters Patent ofthe United States is:

l. A signal mechanism comprising an electrical circuit having an electric light bulb therein, a movable switch arm and a fixed contact in said circuit, said switch arm engageable with said fixed contact to close said circuit, and structure for resetting said signal mechanismfandA automatically checking the operativeness of said bulb and circuit comprising a manually movable element/partial movement of said manually movable element causingmovement of said switch arm to a reset position whereby said switch arm is out of engagement with said fixed contact, further movement of said movable'element -causing closing of-vsaid circuit while said arm-is in reset position whereby the operativeness `of said bulb and circuit is checked.

n Y2. A signal mechanismcomprising an electrical circuit having an` electric lightbulb therein, a toggle spring switcharm` andra -iixed contactin said circuit, -said toggle-spring switch arm engageable with said fixed contact to close said circuit,'said toggle springswitch arm having a spring element to retain said toggle spring switch -arm in engagement with said fixed contact, and

'bulb and circuit comprisinga manually movable element, partial movement of said manually movable element causing movement of said toggle spring switch arm to reset position whereby said toggle spring switch arm is out of engagement with said xed contact, said spring element retaining said toggle spring switch arm out of engagement with said fixed contact, and an auxiliary contact portion engageable with said xed contact while said toggle spring switch arm is in said reset position for completing said circuit, further movement of said movable element causing engagement of said auxiliary contact portion with said iixed contact,

3. A signal mechanism comprising an electrical circuit having an electric light bulb therein, a movable switch arm and a fixed contact in said circuit, said switch arm carrying a U-shaped co-ntact member having only one leg thereof engageable with said iixed contact when said arm is in a closed position with respect to said fixed contact, said xed contact positioned between the legs of said U-shaped contact member, means for res-etting said signal mechanism and automatically checking the operativeness of said bulb and circuit comprising a plunger, partial movement of said plunger moving said switch arm to a reset open position with respect to said fixed Contact whereby none of said legs will be in contact with said xed contact, further movement of said plunger causing the other of said legs to come into contact with said xed contact whereby the operativeness of said bulb and circuit is checked.

4. A signal mechanism comprising an electrical circuit having an electric light bulb therein, switch means in said circuit for opening and closing said circuit comprising a xed contact and a movable contact, said movable contact carried by a movable switch arm, each of said contacts comprising a substantial V-shaped portion having two legs, said xed contact V-shaped portion being smaller than said movable contact V-shaped portion and substantially disposed within said movable contact V-shaped portion whereby the legs of said movable contact V-shaped portion surround the legs of said iixed contact V-shaped portion in spaced relationship, the apexes of said V-shaped portions pointed in a substantially identical direction, means for moving said switch arm to a closed position whereby one leg of said movable contact V-shaped portion will contact one leg of said fixed contact V-shaped portion, means for resetting said signal mechanism and checking the operativeness of said circuit and bulb comprising a plunger, partial depression of said plunger moving said switch arm whereby said movable contact one leg will be out of contact with said xed contact one leg, further depression of said plunger moving the other of said movable contact V-shaped portion legs into contact with the other of said fixed contact V-shaped portion legs.

5. A signal mechanism comprising an electrical circuit having an electric light bulb therein, means for closing said circuit to light said bulb comprising a toggle spring switch arm and a xed contact in said circuit, said toggle spring switch arm comprising a thin resilient strip of metal, said strip having a wide I-shaped hole punched therein between a central portion thereof and one end portion thereof dening two opposed tabs, a coil spring between said tabs, said tabs entering opposite end portions of said coil spring, two parallel thin slots extending from a bottom and top edge of said I-like hole towards but short of another end portion of said strip, a portion of said strip between said parallel slots being rigidly xed and said one end portion free for movement above and below said fixed portion, said free end portion having a resilient U-shaped contact mounted thereon engageable with said fixed contact, said xed contact positioned between the legs of said U-shaped contact and said legs spaced from said fixed contact when said circuit is open, means for moving said free end portion below said fixed portion whereby only one of said legs will contact said xed contact, said coil spring retaining said one leg and xed contact in engagement, and means for resetting said signal mechanism comprising a plunger, partial depression of said plunger causing movement of said free end portion above said xed portion whereby said legs are spaced from said xed contact, said coil spring retaining said legs spaced from said fixed contact, further depression of said plunger moving the other of said legs into contact with said xed contact to complete said circuit for testing the operativeness of said bulb and said circuit.

References Cited in the lle of this patent UNITED STATES PATENTS Number Name Date 2,457,069 Rauh Dec. 21, 1948 2,468,945 Sasser May 3, 1949 2,550,673 Cufalo May 1, 1951 

